Almost all software engineers learn a passing amount of English - truly localized programming environments are quite esoteric and not really available for most

Almost all software engineers learn a passing amount of English - truly localized programming environments are quite esoteric and not really available for most mainstream use cases I can think of. Depending on the company culture and policy, the most common thing to see is a mix of English variable and function names with native-language comments. Occasionally you will see native-language variable and function names. This is much more common in Latin character set languages (especially among Spanish and Portuguese speakers) in my experience; almost all Chinese code seems to use approximately-English variable and function names.